package com.ncmem.utils;
import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.security.Key;
import java.security.Security;

import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

import com.ncmem.model.FileInf;
import org.apache.tomcat.util.http.fileupload.FileItem;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import sun.misc.BASE64Decoder;

/**
 *
 * @author zysoft
 * 用法：
 *
 */
public class CryptoTool
{
    private String key = "2C4ED1CC9BAA42A9";
    private String iv = "2C4ED1CC9BAA42A9";
    //算法名称
    private String KEY_ALGORITHM = "AES";
    //加密算法，填充方式
    private String algorithm = "AES/CBC/NoPadding";

    public CryptoTool()
    {
    }

    public String encrypt(String data) {
        try
        {
            Cipher cipher = Cipher.getInstance(this.algorithm,"BC");
            int blockSize = cipher.getBlockSize();

            //ZeroPadding
            byte[] dataBytes = data.getBytes();
            int plaintextLength = dataBytes.length;
            if (plaintextLength % blockSize != 0) {
                plaintextLength = plaintextLength + (blockSize - (plaintextLength % blockSize));
            }

            byte[] plaintext = new byte[plaintextLength];
            System.arraycopy(dataBytes, 0, plaintext, 0, dataBytes.length);

            SecretKeySpec keyspec = new SecretKeySpec(key.getBytes(), this.KEY_ALGORITHM);
            IvParameterSpec ivspec = new IvParameterSpec(iv.getBytes());

            cipher.init(Cipher.ENCRYPT_MODE, keyspec, ivspec);
            byte[] encrypted = cipher.doFinal(plaintext);

            return new sun.misc.BASE64Encoder().encode(encrypted);

        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    public String decrypt(String data) {
        try
        {
            byte[] encrypted1 = new BASE64Decoder().decodeBuffer(data);

            Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
            Cipher cipher = Cipher.getInstance(this.algorithm,"BC");
            SecretKeySpec keyspec = new SecretKeySpec(key.getBytes(), this.KEY_ALGORITHM);
            IvParameterSpec ivspec = new IvParameterSpec(iv.getBytes());

            cipher.init(Cipher.DECRYPT_MODE, keyspec, ivspec);

            byte[] original = cipher.doFinal(encrypted1);
            String originalString = new String(original);
            return originalString;
        }
        catch (Exception e)
        {
            e.printStackTrace();
            return null;
        }
    }
    public String encrypt(byte[] dataBytes) {
        try
        {
            Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
            Cipher cipher = Cipher.getInstance(this.algorithm,"BC");
            int blockSize = cipher.getBlockSize();

            //ZeroPadding
            //byte[] dataBytes = data.getBytes();
            int plaintextLength = dataBytes.length;
            if (plaintextLength % blockSize != 0) {
                plaintextLength = plaintextLength + (blockSize - (plaintextLength % blockSize));
            }

            byte[] plaintext = new byte[plaintextLength];
            System.arraycopy(dataBytes, 0, plaintext, 0, dataBytes.length);

            SecretKeySpec keyspec = new SecretKeySpec(key.getBytes(), this.KEY_ALGORITHM);
            IvParameterSpec ivspec = new IvParameterSpec(iv.getBytes());

            cipher.init(Cipher.ENCRYPT_MODE, keyspec, ivspec);
            byte[] encrypted = cipher.doFinal(plaintext);

            return new sun.misc.BASE64Encoder().encode(encrypted);

        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    public String decrypt(String data, String encode) {
        try
        {
            byte[] encrypted1 = new BASE64Decoder().decodeBuffer(data);

            Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
            Cipher cipher = Cipher.getInstance(this.algorithm,"BC");
            SecretKeySpec keyspec = new SecretKeySpec(key.getBytes(), this.KEY_ALGORITHM);
            IvParameterSpec ivspec = new IvParameterSpec(iv.getBytes());

            cipher.init(Cipher.DECRYPT_MODE, keyspec, ivspec);

            byte[] original = cipher.doFinal(encrypted1);
            String originalString = new String(original,encode);
            return originalString.trim();
        }
        catch (Exception e)
        {
            e.printStackTrace();
            return null;
        }
    }

    public byte[] encrypt(FileItem data) {
        try
        {
            Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
            Cipher cipher = Cipher.getInstance(this.algorithm,"BC");
            int blockSize = cipher.getBlockSize();

            InputStream stm = data.getInputStream();
            byte[] dataBytes = new byte[(int)data.getSize()];
            stm.read(dataBytes);
            stm.close();
            //ZeroPadding
            //byte[] dataBytes = data.getInputStream().
            int plaintextLength = dataBytes.length;
            if (plaintextLength % blockSize != 0) {
                plaintextLength = plaintextLength + (blockSize - (plaintextLength % blockSize));
            }

            byte[] plaintext = new byte[plaintextLength];
            System.arraycopy(dataBytes, 0, plaintext, 0, dataBytes.length);

            SecretKeySpec keyspec = new SecretKeySpec(key.getBytes(), this.KEY_ALGORITHM);
            IvParameterSpec ivspec = new IvParameterSpec(iv.getBytes());

            cipher.init(Cipher.ENCRYPT_MODE, keyspec, ivspec);
            byte[] encrypted = cipher.doFinal(plaintext);
            return encrypted;

        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    public ByteArrayOutputStream decrypt(FileItem block,int lenOri) {
        try
        {
            InputStream stm = block.getInputStream();
            byte[] dataBytes = new byte[(int)block.getSize()];
            stm.read(dataBytes);
            stm.close();

            Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
            Cipher cipher = Cipher.getInstance(this.algorithm,"BC");
            SecretKeySpec keyspec = new SecretKeySpec(key.getBytes(), this.KEY_ALGORITHM);
            IvParameterSpec ivspec = new IvParameterSpec(iv.getBytes());

            cipher.init(Cipher.DECRYPT_MODE, keyspec, ivspec);

            byte[] out = cipher.doFinal(dataBytes);
            ByteArrayOutputStream ost = new ByteArrayOutputStream();
            ost.write(out,0,lenOri);
            return ost;
        }
        catch (Exception e)
        {
            e.printStackTrace();
            return null;
        }
    }

    public ByteArrayOutputStream decrypt(String aligo, ByteArrayOutputStream block, int len)
    {
        if(aligo.equalsIgnoreCase("sm4")) return this.sm4_decode(block);
        return this.aes_decode(block, len);
    }

    public ByteArrayOutputStream decrypt(String aligo, ByteArrayOutputStream block)
    {
        if(aligo.equalsIgnoreCase("sm4")) return this.sm4_decode(block);
        return this.aes_decode(block);
    }
    /**
     * aes/cbc/pkcs
     * @param s  加密后的数据(16byte对齐)
     * @return
     */
    private ByteArrayOutputStream aes_decode(ByteArrayOutputStream s) {

        try
        {
            byte[] buf = s.toByteArray();
            String ago="AES/CBC/PKCS5Padding";
            this.KEY_ALGORITHM="AES";

            Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
            Cipher cipher = Cipher.getInstance(ago, BouncyCastleProvider.PROVIDER_NAME);
            SecretKeySpec keyspec = new SecretKeySpec(key.getBytes(), this.KEY_ALGORITHM);
            IvParameterSpec ivspec = new IvParameterSpec(iv.getBytes());

            cipher.init(Cipher.DECRYPT_MODE, keyspec, ivspec);

            byte[] out = cipher.doFinal(buf);
            ByteArrayOutputStream ost = new ByteArrayOutputStream();
            ost.write(out,0,out.length);
            return ost;
        }
        catch (Exception e)
        {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * SM4/ECB/PKCS5Padding
     * @param s
     * @return
     */
    private ByteArrayOutputStream sm4_decode(ByteArrayOutputStream s)
    {
        try
        {
            byte[] buf = s.toByteArray();
            String ago="SM4/CBC/PKCS5Padding";
            this.KEY_ALGORITHM="SM4";

            Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
            Cipher cipher = Cipher.getInstance(ago, BouncyCastleProvider.PROVIDER_NAME);
            SecretKeySpec keyspec = new SecretKeySpec(key.getBytes(), this.KEY_ALGORITHM);
            IvParameterSpec ivspec = new IvParameterSpec(iv.getBytes());

            cipher.init(Cipher.DECRYPT_MODE, keyspec, ivspec);

            byte[] out = cipher.doFinal(buf);
            ByteArrayOutputStream ost = new ByteArrayOutputStream();
            ost.write(out,0,out.length);
            return ost;
        }
        catch (Exception e)
        {
            e.printStackTrace();
            return null;
        }
    }
    /**
     * 解密数据
     * @param block  加密后的数据(16byte对齐)
     * @param lenOri 原始大小
     * @return
     */
    private ByteArrayOutputStream aes_decode(ByteArrayOutputStream block, int lenOri) {
        try
        {
            byte[] buf = block.toByteArray();

            Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
            Cipher cipher = Cipher.getInstance(this.algorithm,BouncyCastleProvider.PROVIDER_NAME);
            SecretKeySpec keyspec = new SecretKeySpec(key.getBytes(), this.KEY_ALGORITHM);
            IvParameterSpec ivspec = new IvParameterSpec(iv.getBytes());

            cipher.init(Cipher.DECRYPT_MODE, keyspec, ivspec);

            byte[] out = cipher.doFinal(buf);
            ByteArrayOutputStream ost = new ByteArrayOutputStream();
            ost.write(out,0,lenOri);
            return ost;
        }
        catch (Exception e)
        {
            e.printStackTrace();
            return null;
        }
    }

    public String token(FileInf f, String action)
    {
        String str = f.id + f.nameLoc + action;
        if(action == "block") str = f.id + f.pathSvr + action;
        str = Md5Tool.getMD5(str);
        try {
            str = this.encrypt(str);
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return str;
    }
}